Laminated ceramic electronic component and method for manufacturing the same

ABSTRACT

In a laminated ceramic electronic component, a side-surface outer electrode includes a first electrode portion including side-surface electrode portions located on first and second side surfaces and wrap-around electrode portions arranged to extend around from the side-surface electrode portions of the first electrode portion to portions of third and fourth side surfaces; and a second electrode portion including side-surface electrode portions located on the third and fourth side surfaces and wrap-around electrode portions arranged to extend around from the side-surface electrode portions of the second electrode portion to portions of the first and second side surfaces. The wrap-around electrode portions of the second electrode portion reach regions covering portions of outermost inner electrodes located at an outermost side portion among inner electrodes, which portions are exposed in the first and second side surfaces.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a laminated ceramic electroniccomponent such as a laminated ceramic capacitor and a method formanufacturing the same.

2. Description of the Related Art

A typical laminated ceramic electronic component is a laminated ceramiccapacitor. A laminated ceramic capacitor includes a substantiallystrip-shaped outer electrode formed on a side surface of a ceramicelement assembly.

For example, Japanese Unexamined Patent Application Publication No.2001-57311 discloses a chip-shaped three-terminal capacitor having astructure in which a pair of end-surface outer electrodes (e.g.,terminal electrodes for signal transmission and reception) and asubstantially strip-shaped side-surface outer electrode (e.g., aterminal electrode for ground) are provided on an outer surface of acapacitor body (ceramic element assembly) (see, for example, claim 1,FIG. 1, and related description in Japanese Unexamined PatentApplication Publication No. 2001-57311).

In addition, as a method for forming the substantially strip-shapedside-surface outer electrode, a method is disclosed in which aconductive paste is applied to a side surface of the ceramic elementassembly and fired (see, for example, paragraphs [0053], [0067], [0068],and the like of Japanese Unexamined Patent Application Publication No.2001-57311).

However, when the conductive paste is applied, due to influence ofrheology of the conductive paste, for example, a side-surface outerelectrode 101 is shaped such that a center portion 101 a in a laminationdirection is raised and thick and end portions 101 b in the laminationdirection are thin as schematically shown in FIG. 6, and the thicknessof the side-surface outer electrode 101 in regions covering portions 102b of uppermost and lowermost inner electrodes (outermost innerelectrodes) 102 a in the lamination direction among a plurality of innerelectrodes 102, which portions 102 b are exposed in a side surface of acapacitor body (ceramic element assembly) 100, tends to be insufficient.In particular, when it is attempted to decrease the entire thickness ofthe side-surface outer electrode with respect to the size of the ceramicelement assembly in order to increase the proportion of obtainedelectrostatic capacity with respect to the volume of a component(laminated ceramic capacitor), the thickness of the side-surface outerelectrode 101 is further decreased at the end portions in the laminationdirection. Thus, water infiltrates through the thin portions of theside-surface outer electrode 101, and moisture resistance reliability isdecreased.

SUMMARY OF THE INVENTION

Accordingly, preferred embodiments of the present invention provide alaminated ceramic electronic component that prevents or significantlyreduces infiltration of water into a ceramic element assembly withoutcausing an increase in the product dimension by increasing an entirethickness of an outer electrode, has high moisture resistancereliability, and has high flexibility in capacitance designing; and amethod for manufacturing the same.

A first laminated ceramic electronic component according to a preferredembodiment of the present invention includes a ceramic element assemblyincluding a plurality of laminated ceramic layers and including firstand second end surfaces opposed to each other, first and second sidesurfaces which connect the first and second end surfaces and are opposedto each other, and third and fourth side surfaces which connect thefirst and second end surfaces and are opposed to each other; a pluralityof inner electrodes provided within the ceramic element assembly andextended to the first and second side surfaces; and a strip-shapedside-surface outer electrode provided on the first, second, third andfourth side surfaces of the ceramic element assembly so as to extendaround the ceramic element assembly and connected to the innerelectrodes extended to the first and second side surfaces. Theside-surface outer electrode extending around the ceramic elementassembly includes a first electrode portion including side-surfaceelectrode portions located on the first and second side surfaces of theceramic element assembly and wrap-around electrode portions arranged soas to extend around from the side-surface electrode portions of thefirst electrode portion to portions of the third and fourth sidesurfaces; and a second electrode portion including side-surfaceelectrode portions located on the third and fourth side surfaces andwrap-around electrode portions arranged so as to extend around from theside-surface electrode portions of the second electrode portion toportions of the first and second side surfaces. The wrap-aroundelectrode portions of the second electrode portion are arranged so as toreach regions covering portions of outermost inner electrodes located atan outermost side portion among the inner electrodes, which portions areexposed in the first and second side surfaces of the ceramic elementassembly.

In the description of preferred embodiments of the present invention,the wrap-around electrode portions of the second electrode portion being“arranged so as to reach regions covering portions of outermost innerelectrodes . . . , which portions are exposed in the first and secondside surfaces of the ceramic element assembly . . . ” indicates thatwhen the exposed portions are already covered with the first electrodeportion, the wrap-around electrode portions of the second electrodeportion are arranged so as to reach the regions covering the portionsexposed in the first and second side surfaces, via the first electrodeportion, and also indicates that when the second electrode portion isformed prior to the first electrode portion, the wrap-around electrodeportions of the second electrode portion are arranged so as to directlycover the portions of the outermost inner electrodes which are exposedin the first and second side surfaces.

In a laminated ceramic electronic component according to a preferredembodiment of the present invention, in order to ensure a sufficientthickness of the side-surface outer electrode at an end portion wherethe thickness of the side-surface outer electrode tends to be small(i.e., the portions covering the exposed portions of the outermost innerelectrodes), the wrap-around electrode portions of the second electrodeportion are arranged so as to reach the regions covering the exposedportions of the outermost inner electrodes which are exposed in thefirst and second side surfaces of the ceramic element assembly. Thus, itis possible to provide a laminated ceramic electronic component that isable to prevent or significantly reduce infiltration of water into theceramic element assembly without causing an increase in the productdimension by increasing the entire thickness of the outer electrode, hashigh moisture resistance reliability, and has high flexibility incapacitance designing.

In addition, a second laminated ceramic electronic component accordingto another preferred embodiment of the present invention includes aceramic element assembly including a plurality of laminated ceramiclayers and including first and second end surfaces opposed to eachother, first and second side surfaces which connect the first and secondend surfaces and are opposed to each other, and third and fourth sidesurfaces which connect the first and second end surfaces and are opposedto each other; a plurality of inner electrodes provided within theceramic element assembly and extended to the first and second sidesurfaces; and a strip-shaped side-surface outer electrode located on thefirst and second side surfaces of the ceramic element assembly andconnected to the inner electrodes extended to the first and second sidesurfaces. The side-surface outer electrode is an electrode whose regionscovering portions of outermost inner electrodes located at an outermostside portion among the plurality of inner electrodes extended to thefirst and second side surfaces, which portions are exposed in the firstand second side surfaces of the ceramic element assembly, are formed byfiring conductive paste films that are applied twice.

Also in the second laminated ceramic electronic component according to apreferred embodiment of the present invention, it is possible to obtainthe same advantageous effects as those described above in the firstlaminated ceramic electronic component according to a preferredembodiment of the present invention.

In addition, a third laminated ceramic electronic component according toyet a further preferred embodiment of the present invention includes aceramic element assembly including a plurality of laminated ceramiclayers and including first and second end surfaces opposed to eachother, first and second side surfaces which connect the first and secondend surfaces and are opposed to each other, and third and fourth sidesurfaces which connect the first and second end surfaces and are opposedto each other; a plurality of inner electrodes provided within theceramic element assembly and extended to the first and second sidesurfaces; and a strip-shaped side-surface outer electrode located on thefirst and second side surfaces of the ceramic element assembly andconnected to the inner electrodes extended to the first and second sidesurfaces. The side-surface outer electrode is arranged such that regionsthereof covering portions of outermost inner electrodes located at anoutermost side portion among the plurality of inner electrodes extendedto the first and second side surfaces, which portions are exposed in thefirst and second side surfaces of the ceramic element assembly, are notthinner than a thinnest portion of each of regions thereof coveringportions of the other inner electrodes which are exposed in the firstand second side surfaces of the ceramic element assembly.

Also in the third laminated ceramic electronic component according to apreferred embodiment of the present invention, it is possible to obtainthe same advantageous effects as those described above in the firstlaminated ceramic electronic component according to a preferredembodiment of the present invention. In other words, by enhancingmoisture resistance in the regions covering the exposed portions of theoutermost inner electrodes where the moisture resistance reliabilitytends to be the lowest, the moisture resistance reliability is increasedand it is possible to obtain a laminated ceramic electronic componenthaving high reliability.

In addition, in the first laminated ceramic electronic componentaccording to a preferred embodiment of the present invention, thewrap-around electrode portions of the second electrode portion arepreferably located on the side-surface electrode portions of the firstelectrode portion.

Since the wrap-around electrode portions of the second electrode portionare located on the side-surface electrode portions of the firstelectrode portion including the side-surface electrode portions locatedon the first and second side surfaces and the wrap-around electrodeportions arranged so as to extend around to the portions of the thirdand fourth side surfaces, the wrap-around electrode portions of thesecond electrode portion are arranged so as to reach the regionscovering the portions of the outermost inner electrodes which areexposed in the first and second side surfaces, in a state where theportions of the inner electrodes which are exposed in the side surfacesof the ceramic element assembly are integrally covered by theside-surface electrode portions of the first electrode portion. Thus, itis possible to provide a laminated ceramic electronic component havinghigher moisture resistance reliability and high reliability ofconnection between the side-surface outer electrode and each innerelectrode, which is meaningful.

In addition, in the first laminated ceramic electronic componentaccording to a preferred embodiment of the present invention, a width ofa narrowest portion of the side-surface outer electrode on the first andsecond side surfaces of the ceramic element assembly is preferablylarger than a width of a narrowest portion of the side-surface outerelectrode on the third and fourth side surfaces of the ceramic elementassembly.

Since the width of the narrowest portion of the first electrode portionA which voluntarily serves to cover the portions of the inner electrodeswhich are exposed in the side surfaces of the ceramic element assemblyis larger than the width of the narrowest portion of the secondelectrode portion B, it is possible to provide a laminated ceramicelectronic component that is able to more reliably prevent orsignificantly reduce infiltration of water into the ceramic elementassembly and has high moisture resistance reliability, which ismeaningful.

In addition, each laminated ceramic electronic component according tothe various preferred embodiments of the present invention, the ceramicelement assembly preferably has a quadrangular prism shape in which eachof the first and second end surfaces is a square, for example.

Since the ceramic element assembly preferably has a quadrangular prismshape in which each of the first and second end surfaces is a square, itis possible to obtain a laminated ceramic electronic component having nodirectivity in the side surfaces of the ceramic element assembly, and itis possible to handle the laminated ceramic electronic component withoutregard to its direction at a time of taping package or mounting.

In the description of preferred embodiments of the present invention,the phrase “each of the first and second end surfaces is a square” isnot limited to a case where each of the first and second end surfaces isliterally a square, but is also a concept of including a case of beingsubstantially a square due to manufacturing tolerances or the like.

In addition, each laminated ceramic electronic component according tothe preferred embodiments of the present invention preferably furtherincludes a plurality of inner electrodes provided within the ceramicelement assembly and extended to the first and second end surfaces, inaddition to the inner electrodes extended to the first and second sidesurfaces; and end-surface outer electrodes located on the first andsecond end surfaces of the ceramic element assembly and connected to theinner electrodes extended to the first and second end surfaces, inaddition to the side-surface outer electrode.

Since the above-described configuration is provided, it is possible toobtain a three-terminal capacitor having a structure including a pair ofend-surface outer electrodes (e.g., terminal electrodes for signaltransmission or reception) and a strip-shaped side-surface outerelectrode (e.g., a terminal electrode for ground) on the surface of theceramic element assembly, which is meaningful.

In addition, a method for manufacturing a laminated ceramic electroniccomponent according to a further preferred embodiment of the presentinvention is a method for manufacturing a laminated ceramic electroniccomponent including a ceramic element assembly including a plurality oflaminated ceramic layers and including first and second end surfacesopposed to each other, first and second side surfaces which connect thefirst and second end surfaces and are opposed to each other, and thirdand fourth side surfaces which connect the first and second end surfacesand are opposed to each other; a plurality of inner electrodes providedwithin the ceramic element assembly and extended to the first and secondside surfaces; and a strip-shaped side-surface outer electrode locatedon the first and second side surfaces of the ceramic element assemblyand connected to the inner electrodes extended to the first and secondside surfaces. The method includes a step of forming the side-surfaceouter electrode, the step including a first application step of applyinga conductive paste to portions of the first and second side surfaces ofthe ceramic element assembly into a strip shape such that the conductivepaste extends from one end side to another end side in a laminationdirection; and a second application step of applying a conductive pasteto regions covering portions of outermost inner electrodes located at anoutermost side portion among the inner electrodes, which portions areexposed in the first and second side surfaces of the ceramic elementassembly, without applying the conductive paste to a center portion inthe lamination direction.

Since, in the method for manufacturing the laminated ceramic electroniccomponent according to a preferred embodiment of the present invention,the step of forming the side-surface outer electrode includes the firstapplication step of applying the conductive paste to the portions of thefirst and second side surfaces of the ceramic element assembly into astrip shape such that the conductive paste extends from one end side toanother end side in the lamination direction; and the second applicationstep of applying the conductive paste to the regions covering theportions of outermost inner electrodes located at an outermost sideportion among the inner electrodes, which portions are exposed in thefirst and second side surfaces of the ceramic element assembly, withoutapplying the conductive paste to the center portion in the laminationdirection as described above, it is possible to ensure a sufficientthickness of the side-surface outer electrode at an end portion wherethe thickness of the side-surface outer electrode tends to be small(portions covering the exposed portions of the outermost innerelectrodes). As a result, it is possible to prevent or significantlyreduce infiltration of water into the ceramic element assembly withoutexcessively increasing the entire thickness of the outer electrode.Accordingly, it is possible to efficiently manufacture a laminatedceramic electronic component that is able to achieve both desiredflexibility in capacitance designing and high moisture resistancereliability.

In addition, in the method for manufacturing the laminated ceramicelectronic component according to a preferred embodiment of the presentinvention, the second application step is preferably a step of applyingthe conductive paste to the third and fourth side surfaces such that theconductive paste extends around from the third and fourth side surfacesto the first and second side surfaces to form wrap-around electrodeportions extending around to the first and second side surfaces.

Since, in the second application step, the conductive paste is appliedto the third and fourth side surfaces such that the wrap-aroundelectrode portions are formed on the first and second side surfaces, theconductive paste is efficiently applied to the regions covering theportions of the outermost inner electrodes which are exposed in thefirst and second side surfaces of the ceramic element assembly, suchthat it is possible to form a side-surface outer electrode that is ableto prevent or significantly reduce infiltration of water into theceramic element assembly without excessively increasing the entirethickness of the outer electrode, which allows various preferredembodiments of the present invention to be made more effective.

In addition, in the method for manufacturing the laminated ceramicelectronic component according to a preferred embodiments of the presentinvention, the second application step is preferably conducted after thefirst application step is conducted.

Since the second application step is preferably conducted after thefirst application step is conducted, a conductive paste pattern (aconductive paste pattern that is to be the second electrode portionafter firing) formed by the second application step is formed so as toreach the regions covering the portions of the outermost innerelectrodes which are exposed in the first and second side surfaces, in astate where the portions of the inner electrodes which are exposed inthe side surfaces of the ceramic element assembly are integrally coveredby a conductive paste pattern (a conductive paste pattern that is to bethe first electrode portion after firing) formed by the firstapplication step. Thus, by subsequently conducting a firing step, it ispossible to reliably manufacture a laminated ceramic electroniccomponent having higher moisture resistance reliability and highreliability of connection between the side-surface outer electrode andeach inner electrode.

The above and other elements, features, steps, characteristics andadvantages of the present invention will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a laminated ceramic capacitor accordingto a preferred embodiment of the present invention.

FIG. 2 is a perspective view of a ceramic element assembly constitutingthe laminated ceramic capacitor according to a preferred embodiment ofthe present invention.

FIG. 3 is a diagram of the laminated ceramic capacitor according to apreferred embodiment of the present invention, as seen from a first sidesurface side.

FIG. 4A is a diagram showing the structure of an inner electrode of thelaminated ceramic capacitor according to a preferred embodiment of thepresent invention, the inner electrode being extended to side surfacesof the ceramic element assembly.

FIG. 4B is a diagram showing the structure of an inner electrode of thelaminated ceramic capacitor according to a preferred embodiment of thepresent invention, the inner electrode being extended to end surfaces ofthe ceramic element assembly.

FIG. 5 is a cross-sectional view showing the configuration of aprincipal portion of the laminated ceramic capacitor according to apreferred embodiment of the present invention.

FIG. 6 is a diagram for explaining a problem of an existing laminatedceramic electronic component.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will bedescribed and the features of various preferred embodiments of thepresent invention will be described in more detail.

FIG. 1 is a perspective view showing the configuration of a laminatedceramic electronic component (for example, a three-terminal laminatedceramic capacitor) according to a preferred embodiment of the presentinvention, FIG. 2 is a perspective view showing the configuration of aceramic element assembly constituting the laminated ceramic capacitor,and FIG. 3 is a diagram of the laminated ceramic capacitor according tothe present preferred embodiment of the present invention, as seen froma first side surface side.

The laminated ceramic capacitor 50 includes a ceramic element assembly10 that is formed preferably by laminating a plurality of ceramic layers3 and that includes a first end surface 1 and a second end surface 2which are opposed to each other, a first side surface 11 and a secondside surface 12 which connect the first and second end surfaces 1 and 2and are opposed to each other, and a third side surface 13 and a fourthside surface 14 which connect the first and second end surfaces 1 and 2and are opposed to each other.

Within the ceramic element assembly 10, a plurality of first innerelectrodes (side-surface extended inner electrodes) 21 are arrangedwhich have a substantially cross planar shape and of which a pair ofopposed end portions 21 x and 21 y are extended to the first and secondside surfaces 11 and 12 as shown in FIG. 4A. In addition, within theceramic element assembly 10, a plurality of second inner electrodes(end-surface extended inner electrodes) 22 are arranged to face thefirst inner electrodes (side-surface extended inner electrodes) 21across the ceramic layers 3 and of which a pair of opposed end portions22 x and 22 y are extended to the first and second end surfaces 1 and 2as shown in FIG. 4B.

The laminated ceramic capacitor 50 includes a substantially strip-shapedside-surface outer electrode 31 that is located on the first, second,third, and fourth side surfaces 11, 12, 13, and 14 of the ceramicelement assembly 10 so as to extend around the ceramic element assembly10 and is connected to the first inner electrodes (side-surface extendedinner electrodes) 21, which are extended to the first and second sidesurfaces 11 and 12.

The laminated ceramic capacitor 50 also includes end-surface outerelectrodes 41 that are located on the first and second end surfaces 1and 2 of the ceramic element assembly 10 and are connected to the secondinner electrodes (end-surface extended inner electrodes) 22, which areextended to the first and second end surfaces 1 and 2.

Furthermore, the side-surface outer electrode 31 includes a firstelectrode portion A including side-surface electrode portions A1 locatedon the first and second side surfaces 11 and 12 and wrap-aroundelectrode portions A2 arranged so as to extend around from theside-surface electrode portions A1 to portions of the third and fourthside surfaces 13 and 14; and a second electrode portion B includingside-surface electrode portions B1 located on the third and fourth sidesurfaces 13 and 14 and wrap-around electrode portions B2 arranged so asto extend around from the side-surface electrode portions B1 to portionsof the first and second side surfaces 11 and 12.

The wrap-around electrode portions B2 of the second electrode portion Bare arranged so as to reach regions covering portions of outermost innerelectrodes 21 a located at the outermost side portion among theplurality of first inner electrodes (side-surface extended innerelectrodes) 21, which portions are exposed in the first and second sidesurfaces 11 and 12 of the ceramic element assembly 10.

Hereinafter, the laminated ceramic electronic component (laminatedceramic capacitor) according to the present preferred embodiment of thepresent invention will be described in further detail.

As described above, the ceramic element assembly 10 constituting thelaminated ceramic capacitor 50 according to the preferred embodiment isformed preferably by laminating the plurality of ceramic layers 3 andincludes the first end surface 1 and the second end surface 2 which areopposed to each other, the first side surface 11 and the second sidesurface 12 which connect the first and second end surfaces 1 and 2 andare opposed to each other, and the third side surface 13 and the fourthside surface 14 which connect the first and second end surfaces 1 and 2and are opposed to each other.

The ceramic element assembly 10 preferably has a substantiallyquadrangular prism shape (a substantially rectangular parallelepipedshape) in which the first and second end surfaces 11 and 12 aresubstantially squares. The corner portions and edge portions of theceramic element assembly 10 are chamfered so as to be rounded.

Here, as shown in FIG. 2, where the distance (length) between the firstand second end surfaces 1 and 2 is defined as L; the direction of thislength L is defined as an L direction; the distance (width) between thefirst and second side surfaces and 12 is defined as W; the direction ofthis width W is defined as a W direction; the distance (thickness)between the third and fourth side surfaces 13 and 14 is defined as T;and the direction of this thickness T is defined as a T direction, theceramic element assembly 10 has a lamination structure including theplurality of ceramic layers 3 which extend in the W direction and the Ldirection and are laminated in the T direction.

It should be noted that the ceramic element assembly 10 preferably has asubstantially prism structure in which the lengths in the W directionand the T direction (i.e., the width W and the thickness T) aresubstantially the same and the first and second end surfaces 1 and 2 aresubstantially squares.

The thickness of each ceramic layer 3 is preferably about 0.5 μm toabout 10 μm, for example.

For example, dielectric ceramic materials such as BaTiO₃, CaTiO₃,SrTiO₃, and CaZrO₃ may be used as the ceramic material of the ceramiclayers 3. In addition, materials obtained by adding accessory componentssuch as Mn compounds, Mg compounds, Si compounds, Co compounds, Nicompounds, and rare-earth element compounds to principal components thatare these materials may also be used, for example.

As described above, the laminated ceramic capacitor 50 according to thepresent preferred embodiment includes, as inner electrodes, theplurality of first inner electrodes (side-surface extended innerelectrodes) 21 extended to the first and second side surfaces 11 and 12and the plurality of second inner electrodes (end-surface extended innerelectrodes) 22 extended to the first and second end surfaces 1 and 2.

The plurality of first inner electrodes (side-surface extended innerelectrodes) 21 and the plurality of second inner electrodes (end-surfaceextended inner electrodes) 22 are alternately laminated (arranged) viathe ceramic layers 3 in a lamination direction of the ceramic elementassembly 10, namely, in the T direction.

In the laminated ceramic capacitor 50 according to the present preferredembodiment, the first inner electrodes (side-surface extended innerelectrodes) 21 are configured to serve as electrodes for ground.

Each first inner electrode 21 preferably has a substantially crossplanar shape as shown in FIG. 4A and is configured such that its centerportion serves as an opposing portion 21 z that faces an opposingportion 22 z of each second inner electrode 22 adjacent thereto acrossthe ceramic layer 3.

In addition, a pair of the opposed end portions 21 x and 21 y of eachfirst inner electrode (side-surface extended inner electrode) 21 areexposed in the first and second side surfaces 11 and 12, respectively,of the ceramic element assembly 10. In other words, each first innerelectrode 21 is arranged so as to extend from the first side surface 11to the second side surface 12.

In the laminated ceramic capacitor 50 according to the present preferredembodiment, the second inner electrodes (end-surface extended innerelectrodes) 22 are configured so as to serve as electrodes for signaltransmission and reception.

Each second inner electrode 22 preferably has a substantially wide-stripshape as shown in FIG. 4B, and a pair of the opposed end portions 22 xand 22 y thereof are exposed in the first and second end surfaces 1 and2, respectively, of the ceramic element assembly 10. In other words,each second inner electrode 22 is arranged so as to extend from thefirst end surface 1 to the second end surface 2.

Each second inner electrode (end-surface extended inner electrode) 22 isconfigured such that its center portion serves as the opposing portion22 z that faces the opposing portion 21 z of each first inner electrode21 adjacent thereto across the ceramic layer 3.

For example, Ni, Cu, Ag, Pd, an Ag—Pd alloy, Au, and the like may beused as the conductive materials of the first and second innerelectrodes 21 and 22.

In addition, each of the thicknesses of the first and second innerelectrodes 21 and 22 is preferably about 0.3 μm to about 2.0 μm, forexample.

In the laminated ceramic capacitor 50 according to the present preferredembodiment, electrostatic capacity occurs in a region where the opposingportion 21 z of each first inner electrode 21 and the opposing portion22 z of each second inner electrode 22 face each other across theceramic layer 3. In the present preferred embodiment, the region wherethe electrostatic capacity occurs is defined as an effective portion.

Meanwhile, an outer side portion region where no first inner electrode21 and no second inner electrode 22 are present along the laminationdirection of the ceramic layers 3 is defined as an outer layer portion.

In the laminated ceramic capacitor 50 according to the present preferredembodiment, an outer layer portion 10 a is present on each of the thirdside surface 13 side and the fourth side surface 14 side of the ceramicelement assembly 10 (see FIG. 2).

It should be noted that the thickness (the dimension along the Tdirection) of each outer layer portion 10 a is preferably equal to butmay be thinner than the dimension (gap dimension) along the W directionfrom each of the first and second side surfaces 11 and 12 of the ceramicelement assembly 10 to each second inner electrode 22. On the otherhand, if the thickness of each outer layer portion 10 a becomesexcessively large, the size of a product is undesirably increased. Thus,in the laminated ceramic capacitor 50 according to the present preferredembodiment, the thickness of each outer layer portion 10 a is preferablyequal to or less than about 60 μm, for example.

As described above, the laminated ceramic electronic component accordingto the present preferred embodiment includes, as outer electrodes, theside-surface outer electrode 31 located on the first and second sidesurfaces 11 and 12 and the end-surface outer electrodes 41 located onthe first and second end surfaces 1 and 2.

The side-surface outer electrode 31 and the end-surface outer electrodes41 are connected to different potentials.

Each of the side-surface outer electrode 31 and the end-surface outerelectrodes 41 preferably has a configuration including a base layer(outer electrode body) and a plating layer located thereon.

In the present preferred embodiment, each of the side-surface outerelectrode 31 and the end-surface outer electrodes includes a base layerobtained by applying and firing a conductive paste containing metalpowder and glass, for example.

For example, Cu, Ni, Ag, Pd, an Ag—Pd alloy, Au, or the like may be usedas the metal constituting the base layer.

The thickness of the base layer is preferably about 10 μm to about 50μm, for example.

For example, Cu, Ni, Ag, Pd, an Ag—Pd alloy, Au, or the like may be usedas the metal constituting the plating layer.

The plating layer may preferably include a plurality of plating layers.The plating layer preferably has, for example, a two-layer structureincluding a Ni plating layer and a Sn plating layer.

The thickness of each layer of the plating layer is preferably about 1μm to about 20 μm, for example, at its thickest portion.

The side-surface outer electrode 31, which serves as an electrode forground in the laminated ceramic capacitor 50 according to the presentpreferred embodiment, is arranged so as to extend around the first,second, third and fourth side surfaces 11 to 14 of the ceramic elementassembly 10.

The side-surface outer electrode 31 needs to be provided on at least thefirst and second side surfaces 11 and 12 of the ceramic element assembly10 to which the first inner electrodes 21 are extended. The side-surfaceouter electrode 31 may not necessarily be provided so as to extendaround the first, second, third and fourth side surfaces 11 to 14 of theceramic element assembly 10. However, when the side-surface outerelectrode 31 is provided so as to extend around the first, second, thirdand fourth side surfaces 11 to 14 of the ceramic element assembly 10, itis possible to obtain a laminated ceramic electronic component having nodirectivity in the side surfaces of the ceramic element assembly 10, andit is possible to handle the laminated ceramic electronic componentwithout regard to its direction at a time of taping package or mounting,which is preferred.

In the laminated ceramic capacitor 50 according to the present preferredembodiment, as described above, the side-surface outer electrode 31includes the first electrode portion A including the side-surfaceelectrode portions A1 located on the first and second side surfaces 11and 12 and the wrap-around electrode portions A2 arranged so as toextend around from the side-surface electrode portions A1 to theportions of the third and fourth side surfaces 13 and 14; and the secondelectrode portion B including the side-surface electrode portions B1located on the third and fourth side surfaces 13 and 14 and thewrap-around electrode portions B2 arranged so as to extend around fromthe side-surface electrode portions B1 to the portions of the first andsecond side surfaces 11 and 12.

The wrap-around electrode portions B2 of the second electrode portion Bare arranged so as to reach the regions covering the portions of theoutermost inner electrodes 21 a located at the outermost side portionamong the plurality of first inner electrodes (side-surface extendedinner electrodes) 21, which portions are exposed in the first and secondside surfaces 11 and 12 of the ceramic element assembly 10, namely, suchthat the lengths of the wrap-around electrode portions B2 are largerthan the thickness dimension of the outer layer portion 10 a.

In other words, in the laminated ceramic capacitor 50 according to thepresent preferred embodiment, in the regions of the side-surface outerelectrode 31 which cover the outermost inner electrodes 21 a, the firstelectrode portion A and the second electrode portion B are arranged soas to overlap each other.

Each of the first electrode portion A and the second electrode portion Bconstituting the side-surface outer electrode is formed preferably byapplying and firing a conductive paste; each of the regions of theside-surface outer electrode 31 which cover the outermost innerelectrodes 21 a preferably has a double-coating structure formed byfiring the conductive paste for forming the first electrode portion Aand the conductive paste for forming the second electrode portion B in astate where these conductive pastes are applied in an overlapped manner(see FIG. 5); and the side-surface outer electrode 31 is formed suchthat the thickness of the side-surface outer electrode 31 in each of theregions covering the outermost inner electrodes 21 a preferably is notsmaller than that of the thinnest portion of each of regions coveringportions of the other first inner electrodes 21 which are exposed in thefirst and second side surfaces 11 and 12 of the ceramic element assembly10 (regions other than the regions covering the exposed portions of theoutermost inner electrodes 21 a).

In other words, the regions covering the exposed portions of theoutermost inner electrodes 21 a are formed such that moisture resistancethereof is not inferior to that of the regions covering the exposedportions of the other first inner electrodes 21.

It should be noted that in FIG. 5, in order for it to be recognized thateach of the regions of the side-surface outer electrode 31 which coverthe outermost inner electrodes 21 a includes a double-coating structure,this portion is illustrated so as to have a structure including twoelectrode layers, but it is thought that the interface between the twolayers cannot be clearly recognized in some cases, depending on thefiring conditions for the side-surface outer electrode 31.

Any of the first electrode portion A and the second electrode portion Bmay be on the lower side, but it is preferred that the first electrodeportion A is on the lower side as described below.

Since the wrap-around electrode portions B2 of the second electrodeportion B are located on the side-surface electrode portions A1 of thefirst electrode portion A, which includes the side-surface electrodeportions A1 located on the first and second side surfaces 11 and 12 andthe wrap-around electrode portions A2 arranged so as to extend around tothe portions of the third and fourth side surfaces 13 and 14, thewrap-around electrode portions B2 of the second electrode portion B arearranged so as to reach the regions covering the portions of theoutermost inner electrodes 21 a which are exposed in the first andsecond side surfaces 11 and 12 in a state where the portions of theinner electrodes 21 which are exposed in the side surfaces of theceramic element assembly 10 are integrally covered by the side-surfaceelectrode portions A1 of the first electrode portion A. Thus, it ispossible to more reliably cover the exposed regions of the innerelectrodes. As a result, it is possible to obtain a laminated ceramicelectronic component having higher moisture resistance reliability andhigh reliability of connection between the side-surface outer electrodeand each inner electrode.

In the laminated ceramic capacitor 50 according to the present preferredembodiment, as described above, a sufficient thickness of a principalportion of the side-surface outer electrode 31 is ensured by providing adouble-coating structure at an end portion where the thickness of eachside-surface electrode portion A1 constituting the side-surface outerelectrode 31 tends to be small (i.e., the regions covering the exposedportions of the outermost inner electrodes 21 a) (see FIG. 5). Thus, itis possible to prevent or significantly reduce infiltration of waterinto the ceramic element assembly without excessively increasing theentire thickness of the outer electrode, and it is possible to enhancethe moisture resistance reliability.

In the present preferred embodiment, the regions of the side-surfaceouter electrode 31 which cover the outermost inner electrodes 21 a arearranged so as to have a double-coating structure, whereas the regionsof the side-surface outer electrode 31 which cover the other innerelectrodes 21 are not arranged so as to have a double-coating structure.By so doing, the entire thickness of the side-surface outer electrode 31is increased, the necessity to reduce the dimension of the ceramicelement assembly 10 in order to make the product dimension within astandard value is eliminated, and it is possible to provide a laminatedceramic electronic component having high flexibility in capacitancedesigning and high moisture resistance reliability.

In the laminated ceramic capacitor 50 according to the present preferredembodiment, the width (the dimension in the L direction) of thenarrowest portion of each of the side-surface electrode portions A1,located on the first and second side surfaces 11 and 12 of the ceramicelement assembly 10, of the first electrode portion A constituting theside-surface outer electrode 31 is preferably larger than the width ofthe narrowest portion of each of the side-surface electrode portions B1located on the third and fourth side surfaces 13 and 14 of the ceramicelement assembly 10 and constituting the second electrode portion B.When the width of the narrowest portion of each of the side-surfaceelectrode portions A1 which function to cover the exposed portions ofthe first inner electrodes 21 of the ceramic element assembly 10 islarger than the width of the narrowest portion of each of theside-surface electrode portions B1 of the second electrode portion B asdescribed above, it is possible to more reliably prevent orsignificantly reduce infiltration of water into the ceramic elementassembly 10.

In the laminated ceramic capacitor 50 according to the present preferredembodiment, the thickness of the first electrode portion A constitutingthe side-surface outer electrode is preferably larger than the thicknessof the second electrode portion B. When the thickness of the firstelectrode portion A is made larger, the thickness of the side-surfaceouter electrode 31 in the regions covering the outermost innerelectrodes 21 a (specifically, the side-surface electrode portions A1)is easily made larger, the width of the side-surface outer electrode 31(specifically, the side-surface electrode portions A1) is easily madelarger, and thus it is possible to further enhance the moistureresistance.

When the thickness of the second electrode portion B is made thinnerthan the first electrode portion A, the necessity to decrease thethickness of each outer layer portion 10 a of the ceramic elementassembly 10 in order to make the product dimension within a standardvalue is eliminated, and it is possible to ensure a sufficient thicknessof each outer layer portion 10 a and enhance the reliability.

The end-surface outer electrodes 41, which serve as electrodes forsignal reception and transmission in the laminated ceramic capacitor 50according to the present preferred embodiment, are located on the firstand second end surfaces 1 and 2 of the ceramic element assembly 10.

It should be noted that each end-surface outer electrode 41 includes anend-surface electrode portion 41 a and a wrap-around electrode portion41 b arranged so as to extend around the first to fourth side surfaces11 to 14.

Next, a non-limiting example of a method for manufacturing the laminatedceramic capacitor according to another preferred embodiment of thepresent invention will be described.

Ceramic green sheets that are to be the ceramic layers, a conductivepaste for inner electrode, and a conductive paste for outer electrodeare prepared.

The ceramic green sheets, the conductive paste for inner electrode, andthe conductive paste for outer electrode each contain a binder and asolvent, and a known binder and a known organic solvent may be used, forexample.

Then, the conductive paste for inner electrode is printed on the ceramicgreen sheet in a predetermined pattern by a method such as screenprinting, thereby forming an inner electrode pattern.

Then, a predetermined number of the ceramic green sheets on whichvarious inner electrode patterns are formed as described above and apredetermined number of ceramic green sheets for outer later on which noinner electrode pattern is formed are laminated in a predeterminedorder, thereby producing a mother laminate.

Then, the mother laminate is pressed in the lamination direction by amethod such as rubber press. The pressed mother laminate is cut into apredetermined size, thereby cutting out a green ceramic elementassembly.

Then, the green ceramic element assembly is fired, thereby obtaining aceramic element assembly. The firing temperature depends on the ceramicmaterial and the inner electrode material but is generally preferablyabout 900° C. to 1300° C.

Next, the fired ceramic element assembly is polished, and the cornersand the edges of the ceramic element assembly are rounded. A method suchas barrel polishing may be used as the polishing method. By so doing,the ceramic element assembly 10 shown in FIG. 2 is obtained.

On the fired ceramic element assembly 10, (a base layer of) aside-surface outer electrode is formed. A typical example of the methodfor forming (the base layer of) the side-surface outer electrode is amethod in which the conductive paste is applied and fired. It should benoted that there is no special constraint on a specific method inapplying and firing the conductive paste, and it is possible toarbitrarily select and use an appropriate method from among variousknown methods.

For example, a method may be used in which, using an apparatus disclosedin Japanese Unexamined Patent Application Publication No. 2001-57311, aconductive paste stored in a paste tank is extruded and applied throughslits formed in a slit plate.

In this case, in an application step for the first time, the conductivepaste is applied to the entireties, in the lamination direction (Tdirection), of the first and second side surfaces (both left and rightside surfaces) 11 and 12 of the ceramic element assembly 10 into asubstantially strip shape. Then, in an application step for the secondtime, the conductive paste is applied to the entireties, in the widthdirection (W direction), of the third and fourth side surfaces (bothupper and lower side surfaces) 13 and 14 of the ceramic element assembly10 into a substantially strip shape. By so doing, it is possible to formthe side-surface outer electrode 31 (FIG. 1) extending around theceramic element assembly 10, and it is also possible to form thewrap-around electrode portions B2 (FIG. 1).

Alternatively, in an application step for the first time, the conductivepaste is applied to the entireties, in the lamination direction (Tdirection), of the first and second side surfaces 11 and 12 of theceramic element assembly 10 into a substantially strip shape. Then, inan application step for the second time, the conductive paste isextruded through slits processed such that the paste is not extrudedfrom its center, whereby it is possible to apply the conductive pasteonly to both end sides, in the lamination direction (T direction), ofthe first and second side surfaces 11 and 12.

It is possible to change the lengths of the wrap-around electrodeportions B2 by adjusting the amounts of the paste extruded through theslits.

In addition, a roller transfer method may be used in which a conductivepaste retained on a roller having a groove, for conductive paste, formedon its circumferential surface is transferred and applied onto thesurface of the ceramic element assembly (see, for example, paragraphs[0092] and [0093] of Japanese Unexamined Patent Application PublicationNo. 2012-28502 and Japanese Unexamined Patent Application PublicationNo. 2001-167989).

When such a roller transfer method is used, the ceramic element assembly10 is retained by a retaining tool, the conductive paste is applied tothe first and second side surfaces (both left and right side surfaces)11 and 12 of the ceramic element assembly 10 as application for thefirst time, and formed conductive paste applied films are dried.

Then, the ceramic element assembly 10 is removed from the retainingtool, rotated 90 degrees (its direction is changed 90 degrees), andretained by the retaining tool again, and the conductive paste isapplied to the third and fourth side surfaces (both upper and lower sidesurfaces) 13 and 14 of the ceramic element assembly 10 as applicationfor the second time. By so doing, it is possible to form theside-surface outer electrode 31 (FIG. 1) extending around the ceramicelement assembly 10 and form the wrap-around electrode portions B2.

It is possible to change the lengths of the wrap-around electrodeportions B2 by adjusting a pressing force applied at a time of rollertransfer.

It should be noted that when either application method is used, it ispreferred that the conductive paste is initially applied to the firstand second side surfaces 11 and 12 in which the inner electrodes 21 areexposed, as described above, but in some cases, it is possible to applythe conductive paste to the third and fourth side surfaces (both upperand lower side surfaces) 13 and 14 of the ceramic element assembly 10for the first time and apply the conductive paste to the first andsecond side surfaces (both left and right side surfaces) 11 and 12 ofthe ceramic element assembly 10 for the second time.

In addition, in applying the conductive paste, in the case where theceramic element assembly 10 has a substantially prism structure, priorto application of the conductive paste, the first and second sidesurfaces 11 and 12 are reliably detected by detecting whether the innerelectrodes 21 are exposed, by using an optical device such as a camera,whereby it is possible to apply the conductive paste to a predeterminedlocation.

Next, base layers of end-surface outer electrodes are formed on the endsurfaces of the ceramic element assembly 10. In forming the base layersof the end-surface outer electrodes, conductive paste applied films forend-surface outer electrode are formed on both end surfaces of theceramic element assembly 10.

Then, the conductive paste applied films formed thus for side-surfaceouter electrode and for end-surface outer electrode are fired. Thefiring temperature is generally preferably about 700° C. to 900° C.

By so doing, the base layer of the side-surface outer electrode and thebase layers of the end-surface outer electrodes are formed.

Then, for example, plating treatment is conducted by a known method suchas electroplating to form plating layers on each base layer. As theplating layer, a Ni plating layer and a Sn plating layer may be formedin order on each base layer.

In this manner, a laminated ceramic capacitor having the structure asshown in FIG. 1 is obtained.

Evaluation of Characteristics (1) Sample Subjected to Evaluation ofCharacteristics

In order to evaluate characteristics of a produced laminated ceramiccapacitor (sample), a three-terminal laminated ceramic capacitor thathas the structure as shown in FIG. 1 and meets the following conditions(a sample of sample number 1 in Table 1) was prepared. In other words,the laminated ceramic capacitor is a laminated ceramic capacitor thatincludes the characteristics and features of a preferred embodiment ofthe present invention where the side-surface outer electrode 31 includesthe first electrode portion A including the side-surface electrodeportions A1 located on the first and second side surfaces 11 and 12 andthe wrap-around electrode portions A2 arranged so as to extend aroundfrom the side-surface electrode portions A1 to the portions of third andfourth side surfaces 13 and 14 and the second electrode portion Bincluding the side-surface electrode portions B1 located on the thirdand fourth side surfaces 13 and 14 and the wrap-around electrodeportions B2 arranged so as to extend around from the side-surfaceelectrode portions B1 to the portions of the first and second sidesurfaces and 12; and the wrap-around electrode portions B2 of the secondelectrode portion B are arranged so as to reach the regions covering theportions of the outermost inner electrodes 21 a located at the outermostside portion among the first inner electrodes 21, which portions areexposed in the first and second side surfaces 11 and 12 of the ceramicelement assembly 10.

Conditions for Sample Number 1

(a) Product dimension

L: 1.0 mm, W: 0.5 mm, T: 0.5 mm

(b) Inner electrode

Thickness: 0.6 μm

Number of inner electrodes (number of layers): 420

First inner electrode (electrodes for ground): 210

Second inner electrode (electrodes for signal): 210

(c) Thickness of outer layer portion: 30 μm

(d) Thickness of side-surface outer electrode covering exposed portionsof outermost inner electrodes: shown in Table 1

In addition, for comparison, a laminated ceramic capacitor (a sample asa comparative example of sample number 2 in Table 1) in which aside-surface electrode is formed only on the first and second sidesurfaces 11 and 12 of the ceramic element assembly 10 was prepared. Thelaminated ceramic capacitor of this comparative example is a laminatedceramic capacitor in which the side-surface outer electrode coveringportions exposed in the first and second side surfaces 11 and 12 of theceramic element assembly 10 has a single-layer structure and are thinand which does not meet the requirements of the present invention.

(2) Evaluation Method (a) Thickness of Side-Surface Outer Electrode

A WT surface (end surface) of each sample was polished until the firstinner electrodes extended to the first and second side surfaces wereexposed. Then, the “thickness of the side-surface outer electrode” inthe region covering the portion of each outermost inner electrode whichis exposed in the first and second side surfaces of the ceramic elementassembly, on the polished cross-section, was measured with a digitalmicroscope (VHX-100 manufactured by KEYENCE CORPORATION). Themeasurement was conducted for each of five samples and the “thickness ofthe side-surface outer electrode” in the region was measured at fourlocations. The total number of data was sample number 5×measurementlocations 4=20.

The minimum value of “the thickness of the side-surface outer electrode”and the average of the “thickness of the side-surface outer electrode”which was calculated from the above data are shown in Table 1.

(b) Moisture Resistance Reliability

Each sample was mounted on a test substrate (substrate thickness: 1.6mm, a single-layer substrate) and placed in a test bath. EHS-211MDmanufactured by ESPEC Corp. was used as the test bath, and AMI-150-S-25manufactured by ESPEC Corp. was used for voltage application/resistancemeasurement.

The test conditions were 85° C./85%/4 V/1000 hr, and a moistureresistance reliability test was conducted for 18 samples.

When the resistance at the end of the test was decreased from the valueat the beginning of the test by a single digit or more in LogIR, theresistance was regarded as defective.

The number of occurrence of resistance defect is also shown in Table 1.

TABLE 1 Number of occurrence of resistance defect in moisture Manner inThickness of resistance which side- side-surface reliability surfaceouter electrode test outer Minimum Number of Sample electrode is valueAverage defects/Number number provided (μm) (μm) of samples 1 (Example)Provided so 5.19 10.35  0/18 as to extend around the first to fourthside surfaces 2 Provided 1.57 5.09 18/18 (Comparative only on Example)first and second side surfaces

(c) Width of Side-Surface Outer Electrode

For the sample of sample number 1 in Table 1, the width of the narrowestportion of each of the side-surface electrode portions A1, located onthe first and second side surfaces 11 and 12, of the first electrodeportion A constituting the side-surface outer electrode 31 and thenarrowest portion of each of the side-surface electrode portions B1 ofthe second electrode portion B located on the third and fourth sidesurfaces 13 and 14, were measured. The measurement was conducted with ametallographical microscope (MM-60 manufactured by Nikon Corporation).

The measurement was conducted for five samples and at each of the firstand second side surfaces 11 and 12 or each of the third and fourth sidesurfaces 13 and 14 of each sample. The total number of data was samplenumber 5×measurement locations 2=10.

The minimum value of the width of the narrowest portion and the averageof the width of the narrowest portion which was calculated from theabove data are shown in Table 2.

TABLE 2 Width of side-surface outer electrode Side surface of ceramicMinimum element assembly value (mm) Average (mm) First side surface and0.224 0.240 second side surface Third side surface and 0.193 0.209fourth side surface

(3) Evaluation Result

As shown in Table 1, in the case of the sample of sample number 1 whichincludes the features and characteristics of a preferred embodiment ofthe present invention, with regard to the “thickness of the side-surfaceouter electrode” in the region covering the exposed portion of eachoutermost inner electrode, the average value and the minimum value are10.35 μm and 5.19 μm, respectively, and are sufficiently higher thanthose of the sample 2 of the comparative example which does not includethe features and characteristics of a preferred embodiment of thepresent invention, namely, an average value of 5.09 μm and a minimumvalue of 1.57 μm. In addition, it is confirmed that occurrence ofresistance decrease in the moisture resistance reliability test was notobserved. It should be noted that in the sample of the comparativeexample of sample number 2, the occurrence of a resistance defect wasobserved in all of the 18 samples.

In addition, with regard to the relationship between the width of thenarrowest portion of each of the side-surface electrode portions A1located on the first and second side surfaces 11 and 12 and the width ofthe narrowest portion of each of the side-surface electrode portions B1located on the third and fourth side surfaces 13 and 14 in the sample ofsample number 1 which includes all of the features and characteristicsof a preferred embodiment of the present invention, it is confirmed thatthe former is higher in both the minimum value of the width of thenarrowest portion and the average value of the width of the narrowestportion, as shown in Table 2.

As presented above, when the width of the narrowest portion of each ofthe side-surface electrode portions A1 located on the first and secondside surfaces (the left and right side surfaces) 11 and 12 in which theinner electrodes 21 are exposed is made larger than that of each of theside-surface electrode portions B1 located on the third and fourth sidesurfaces (the upper and lower side surfaces) 13 and 14, it is possibleto enhance the moisture resistance reliability, which is preferred.

The above preferred embodiments have been described with, as an example,the three-terminal laminated ceramic capacitor from which theadvantageous effects of the present invention are expected most.However, in the present invention, the type of the laminated ceramicelectronic component is not limited thereto, and preferred embodimentsof the present invention are applicable to various laminated ceramicelectronic components including a substantially strip-shapedside-surface outer electrode.

For example, preferred embodiments of the present invention are alsoapplicable to a laminated ceramic electronic component including innerelectrodes extended to side surfaces but having no inner electrodesextended to end surfaces.

In addition, preferred embodiments of the present invention are alsoapplicable to a laminated ceramic electronic component including aplurality of substantially strip-shaped side-surface externalelectrodes, such as a multilayer capacitor array.

Furthermore, the present invention is not limited to the above preferredembodiments in other aspects, and with regard to the number of, thedimensions of, and the shapes of the ceramic layers or the innerelectrodes constituting the ceramic element assembly, variousapplications and modification may be made within the scope of thepresent invention.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

What is claimed is:
 1. A method for manufacturing a laminated ceramicelectronic component including: a ceramic element assembly including aplurality of laminated ceramic layers and including first and second endsurfaces opposed to each other, first and second side surfaces whichconnect the first and second end surfaces and are opposed to each other,and third and fourth side surfaces which connect the first and secondend surfaces and are opposed to each other; a plurality of innerelectrodes provided within the ceramic element assembly and extended tothe first and second side surfaces; and a strip-shaped side-surfaceouter electrode located on the first and second side surfaces of theceramic element assembly and connected to the inner electrodes extendedto the first and second side surfaces, the method comprising: a step offorming the side-surface outer electrode, the step including: a firstapplication step of applying a conductive paste to portions of the firstand second side surfaces of the ceramic element assembly into a stripshape such that the conductive paste extends from one end side toanother end side in a lamination direction; and a second applicationstep of applying a conductive paste to regions covering portions ofoutermost inner electrodes located at an outermost side portion amongthe inner electrodes, which portions are exposed in the first and secondside surfaces of the ceramic element assembly, without applying theconductive paste to a center portion in the lamination direction.
 2. Themethod according to claim 1, wherein the second application step is astep of applying the conductive paste to the third and fourth sidesurfaces such that the conductive paste extends around from the thirdand fourth side surfaces to the first and second side surfaces to formwrap-around electrode portions extending around to the first and secondside surfaces.
 3. The method according to claim 1, wherein the secondapplication step is conducted after the first application step isconducted.
 4. The method according to claim 2, wherein the secondapplication step is conducted after the first application step isconducted.